The Third Biennial Mammalian Developmental Genetics Workshop will be held in Bar Harbor, 8-12 September, 1993. This Third Workshop builds on the highly successful workshops held in Bar Harbor in 1989 and 1991. Emphasis will be placed on the mouse as a model species. The program will consist of keynote presentations, topic sessions, and 'brainstorming' sessions. Keynote presentations will provide an overview of broad developmental questions; topic sessions will emphasize specific developmental problems; and 'brainstorming' meetings will emphasize strategies for studying important but poorly understood developmental problems. For the Third Workshop, the keynote presentations will focus on genes that control mouse development and on the genetics of human birth defects; topic sessions will focus on the genetics of hearing and vision, gene expression in early development, the genetic control of lineage determination and the genetic control of sex determination and gametogenesis; and 'brainstorming' sessions will focus on the developmental impact of environmental insults and on the genetic control of programmed cell death. Each topic session will begin with an invited 60 minute presentation providing an overview of the research problems and progress for the subject of that section. These overviews will be followed by two or three 20 minute, more narrowly focused, complementary presentations. Presenters will be selected by the Organizers from attendee applications. Attendance will be limited to 110. Participation of graduate students and postdoctoral fellows in encouraged. Abstracts will be provided to attendees but will not be published. Poster presentations are encouraged. The other major mouse developmental genetics meetings are the Gordon Conference on Embryogenesis and Gametogenesis and the Cold Spring Harbor-Heidelberg Mouse Molecular Genetics meeting. Because the subject emphasis is different and because it is held in the "off-year" of the Gordon Conference and during the year when the Mouse Molecular Genetics Workshop if held in Heidelberg, the Bar Harbor Workshop complements these meetings in subject and timing.